Refractory material and process of producing the same



- Patented May 1, 1928..

UNITED STATES PATENT orr es.

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no Drawing, original application fled Kay 19, 1923, Serial in). 640,228. Dividedand this application med an? 1c, 1925. Serial m. 2,868.

, Our invention, although not limited thereto, concerns more partlcularly material, such as safe and vault plates and the like, adapted to resist attack by the local application ofhigh heat, asby means of the oxy-acetylene torch. The sub ect matter set forth in this application is divided from our application Serial No. 640,226, filed May 19,

' 1923, and having the title: Alloys and materials "employing the same. It haslong been known that copper, because of its high heat conductivity and the fact that it cannot be cut by oxidation, oflers substantial resistance to penetration by. means of high heat locally 'iapplied. It has been found defective, however, forthe reason that its melting point is relatively low and also because 1t flows I freely when it has been brought to a melting temperature. We havefound a way to raise the melting point of copper and, at the same time, preserve or increase its high heat conductivity and also to produce a material I which does not flow when brought to a melting temperature as by the local apphcatlon of high heat. We accomplish these results .by the addition to'copper of relatively small amounts of silicon and carbon, it having been found that such addition profoundly afiects the physical qualities of the copper,

producing a material having the characteristicsabove stated. A typical formula of suchan alloy would be approximately as follows, disregarding the -impurities commonly. found in refined copper, such as small 5 amounts of iron, lead and tin which may be present without serious detriment tliereto:

to add a nished by the drippings from the electrodes.

After the metalhas been brought to a high heat, we add thereto from 2 to 2 by weight of 30% cupro-silicon in powdered form. The alloying takes place very quickly NVlth much loss of heat and a notable change takes place in the color'of the molten metal. It 1s necessary to stir the metal rapidly; otherwise, this alloyin will be largely a surface phenomenon an the surface of the molten bath will tend; to freeze. After the metals are thoroughly mixed,'the alloy can be pouredin the regular Way, as by means o f .a ladle. As an alternative the cupro- SlllCOIl can be made molten and can be mixed with the copper while the latter is either in the furnace or the ladle.

The resulting alloy resists best when the silicon content is from .60 to .75. If greater or less amounts of silicon are added, there is alnotable change in theresistance of the metal. If too great an amount of silicon is added, then theresistance of the alloy becomes less than that of copper? In a previous application. we have described material characterized by a corehaving a high-melting point, encompassed b another metal, termed by us the sheath metal, preferably having high heat conductivity. The alloy disclosed above makes an excellent sheath metal, inasmuch as it cannot be cut by oxidation and yields very slowly wheni extremely high heat is locally applied. As pointed out above, this alloy will not flow when raised above its meltihg point but appears to slowly slough off, in

very small fl Another method of utilizing this alloy is I to. use the same as a core and to encompass.

the alloy in other metal, such as fcastiron,

- steel and the like. Here the core and sheath will be rigidly united, the areas in contact being, in fact, alloys of the core and sheath materials. .On account of its-very high heat conductivity and its other-peculiar properties it has been foundthat such a core will resist prolonged attacksby means of the oxyacetylene torch. The encompassing ofthis alloy in another metal permits its use in much thinner strata. Tests have shown that these are impenetrable to the torch, notwithstanding the fact that the same thickness of the alloynot so encompassed is penetrated with relative case. It has also been found that an alloyjof copper and silicon is superior to copper and other non-ferrous metals when used either as a sheath metal as de-. scribed above, or as a core encompassed by other metals.

is When using the alloy herein described as a.

core, wemay combineanother metal (as castiron) therewith and 'then encompass the whole in a suitable sheath metal such as steel. In such case, the alloy may form from to 30 per cent of the core.

So-called torch-resisting plates have'heretofore been suggested in which copper and cast iron in varied proportions have been combined. The best results can be obtained in such plates when the copper content is ap-j Having now described our invention, whatwe claim and desire to secure by cut is as follows 1. As a new material, an alloy consisting Letters Patof copper, approximately .60 to .7 5% silicon, and less than 1% carbon.

'2. As a new material, an alloy consisting of copper, approximately .60 to .7 5% silicon and .015 to 020% carbon. As a new material, an alloy of copper of over 99%, and silicon and carbon 00.111- pleting the remainder with the silicon materially predominating the carbon.

4. As a new material, an alloy of copper,

silicon and carbon having the copper as the main ingredient and the silicon below .75%

and the carbon less than one-half of 1%,

said alloy having a higher melting point and higher heat conductivity than copper.

5. As a new inaterial, an alloy of copper, silicon and carbon havingthe copper as the main ingredient and the silicon below .7 5% and the carbon less than one-half of 1%, said alloy presenting the characteristic of not flowing when-raised by local high heat to 'a'point above the boiling point thereof.

6. The method of making an alloy of carbon, silicon and copper which consists in heating the copper, adding carbon during the melting thereby assisting in deoxidation, adding from two to two and one half percent by weight of 30% powdered cupro-silicon, stirring rapidly, and pouring. I I

This specification signed this 8 day of J any, 1925.

JOSEPH G. DONALDSON. HENRY L. GOLES. 

